A simple analog division scheme

A technique for analog division of two voltage signals that offers high accuracy (0.5%) and relatively good response, especially when the numerator value is nearly constant, is presented. The proposed method is based on the relation of a signal's frequency to its period. The basic idea is to convert input voltage to frequency (through a voltage-controlled oscillator (VCO)) and then produce an output voltage proportional to the period of this signal. The circuit implementing this method is easy to build and may be used in many instrumentation and control applications where the reciprocal of a voltage is needed. Supporting experimental results and performance measurements are also given. >